2 types of exceptions in Java

Lora 155 Published: 10/27/2024

2 types of exceptions in Java

I'll respond in English as requested!

There are two main types of exceptions in Java: checked exceptions and unchecked exceptions.

Checked Exceptions: These are exceptions that must be explicitly handled by the programmer using a try-catch block or by using a throws clause when declaring a method. Checked exceptions are typically subclasses of the Exception class. When a method declares that it will throw a checked exception, the caller method must also declare that it can handle this exception. This ensures that the exception is properly handled and does not propagate to the top-level of the program.

Example:

public void someMethod() throws IOException {
// code that might throw an IOException
}

Unchecked Exceptions (also known as runtime exceptions): These are exceptions that are not checked by the compiler and can occur at runtime. Unchecked exceptions are typically subclasses of the RuntimeException class or its subclasses. They do not need to be explicitly handled using a try-catch block, although it is still good practice to handle them properly.

Example:

public void someMethod() {
int i = 5 / 0; // throws an ArithmeticException (unchecked)
}

Some common unchecked exceptions in Java include:

ArithmeticException: thrown when an arithmetic operation results in a divide-by-zero or overflow/underflow. NullPointerException: thrown when you try to access or manipulate a null object reference.

ClassCastException: thrown when you try to cast an object to a class that it's not compatible with.

In contrast, some common checked exceptions in Java include:

IOException: thrown when an I/O operation fails, such as reading from or writing to a file that does not exist. SQLException: thrown when a database query fails due to errors such as invalid queries or connection problems.

Handling checked exceptions involves using try-catch blocks and/or re-throwing the exception up the call stack. For unchecked exceptions, it's usually sufficient to catch them at the point where they occur and handle them accordingly.

How many types of exceptions in java javatpoint

I'd be happy to help you with that!

According to Javatpoint, an online learning platform for Java programming, there are several types of exceptions in Java. Here are some of the key ones:

Checked Exception: These are exceptions that must be explicitly handled by a catch block or propagated through method calls. Examples include IOException, SQLException, and FileNotFoundException. Unchecked Exception: Also known as "runtime exceptions," these are exceptions that can occur at runtime, such as ArithmeticException, ArrayIndexOutOfBoundsException, and ClassCastException. These exceptions do not need to be explicitly handled by a catch block. Error: Errors are severe programming errors, such as OutOfMemoryError, StackOverflowError, and LinkageError. Unlike runtime exceptions, these cannot be caught or propagated through method calls. RuntimeException: This is an abstract class that is the superclass of all unchecked exceptions (runtime exceptions). Examples include ArrayIndexOutOfBoundsException and ClassCastException.

Exception: This is an abstract class that is the superclass of all checked exceptions. Examples include IOException, SQLException, and FileNotFoundException. All Exception subclasses are either runtime exceptions or errors. IOException: A subclass of Exception, this represents exceptions that occur during input/output operations, such as file I/O, network I/O, or database I/O. SecurityException: A subclass of Exception, this represents security-related exceptions that can occur when a program attempts to perform an unauthorized operation. ExceptionInInitializerError: A subclass of RuntimeException, this represents an exception that occurs during the initialization of an object or class. LinkageError: A subclass of Error, this represents errors that occur while linking classes together, such as loading a class that is not found or contains incorrect bytecode. VerifyError: A subclass of Error, this represents errors that occur when verifying the correctness of bytecode, such as attempting to access an inaccessible field or method.

In summary, Java has several types of exceptions, including checked and unchecked exceptions, runtime exceptions, and errors. Understanding these different exception types is crucial for writing robust and reliable Java programs.

Would you like me to elaborate on any specific type of exception?